Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA.
Malar J. 2012 May 11;11:162. doi: 10.1186/1475-2875-11-162.
Several studies indicate that people of the Fulani ethnic group are less susceptible to malaria compared to those of other ethnic groups living sympatrically in Africa, including the Dogon ethnic group. Although the mechanisms of this protection remain unclear, the Fulani are known to have higher levels of Plasmodium falciparum-specific antibodies of all Ig classes as compared to the Dogon. However, the proportions of B cell subsets in the Fulani and Dogon that may account for differences in the levels of Ig have not been characterized.
In this cross-sectional study, venous blood was collected from asymptomatic Fulani (n = 25) and Dogon (n = 25) adults in Mali during the malaria season, and from P. falciparum-naïve adults in the U.S. (n = 8). At the time of the blood collection, P. falciparum infection was detected by blood-smear in 16% of the Fulani and 36% of the Dogon volunteers. Thawed lymphocytes were analysed by flow cytometry to quantify B cell subsets, including immature and naïve B cells; plasma cells; and classical, activated, and atypical memory B cells (MBCs).
The overall distribution of B cell subsets was similar between Fulani and Dogon adults, although the percentage of activated MBCs was higher in the Fulani group (Fulani: 11.07% [95% CI: 9.317 - 12.82]; Dogon: 8.31% [95% CI: 6.378 - 10.23]; P = 0.016). The percentage of atypical MBCs was similar between Fulani and Dogon adults (Fulani: 28.3% [95% CI: 22.73 - 34.88]; Dogon: 29.3% [95% CI: 25.06 - 33.55], but higher than U.S. adults (U.S.: 3.0% [95% CI: -0.21 - 6.164]; P < 0.001). Plasmodium falciparum infection was associated with a higher percentage of plasma cells among Fulani (Fulani infected: 3.3% [95% CI: 1.788 - 4.744]; Fulani uninfected: 1.71% [95% CI: 1.33 - 2.08]; P = 0.011), but not Dogon adults.
These data show that the malaria-resistant Fulani have a higher percentage of activated MBCs compared to the Dogon, and that P. falciparum infection is associated with a higher percentage of plasma cells in the Fulani compared to the Dogon, findings that may account for the higher levels of P. falciparum antibodies in the Fulani.
多项研究表明，与生活在非洲的其他族群相比，富拉尼族对疟疾的抵抗力较弱，包括多贡族。尽管这种保护的机制尚不清楚，但已知与多贡族相比，富拉尼族具有更高水平的所有免疫球蛋白类别的疟原虫特异性抗体。然而，富拉尼族和多贡族中可能导致免疫球蛋白水平差异的 B 细胞亚群的比例尚未得到描述。
在这项横断面研究中，在疟疾季节从马里无症状的富拉尼族（n = 25）和多贡族（n = 25）成年人以及来自美国无疟原虫感染的成年人（n = 8）中采集静脉血。在采血时，16%的富拉尼族和 36%的多贡族志愿者的血液涂片检测到疟原虫感染。通过流式细胞术分析解冻的淋巴细胞，以定量 B 细胞亚群，包括未成熟和幼稚 B 细胞、浆细胞以及经典、激活和非典型记忆 B 细胞（MBCs）。
富拉尼族和多贡族成年人的 B 细胞亚群总体分布相似，尽管富拉尼族中激活的 MBC 百分比更高（富拉尼族：11.07%[95%CI：9.317-12.82]；多贡族：8.31%[95%CI：6.378-10.23]；P = 0.016）。富拉尼族和多贡族成年人的非典型 MBC 百分比相似（富拉尼族：28.3%[95%CI：22.73-34.88]；多贡族：29.3%[95%CI：25.06-33.55]，但高于美国成年人[美国：3.0%[95%CI：-0.21-6.164]；P < 0.001）。疟原虫感染与富拉尼族中浆细胞的百分比增加有关（富拉尼族感染：3.3%[95%CI：1.788-4.744]；富拉尼族未感染：1.71%[95%CI：1.33-2.08]；P = 0.011），但在多贡族成年人中没有发现这种关系。
这些数据表明，与多贡族相比，抗疟的富拉尼族具有更高比例的激活 MBC，与多贡族相比，疟原虫感染与富拉尼族中浆细胞的百分比增加有关，这些发现可能解释了富拉尼族中更高水平的疟原虫抗体。
